Adjusting means for the backs of type-writer chairs.



Patented May 1, 1917.

H. W. BOLENS.

ADJUSTING MEANS FOR THE BACKS OF TYPE WRITER CHAIRS.

APPLICATION FILED SEPT-2|. 1915.

[3/ INVENTOR:

By W

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HARRY W. BOLENS, 0F PORT WASHINGTON, WISCONSIN.

Specification of Letters Patent.

Patented May 1, 1917.

Application filed September 21, 1915. Serial No. 51,784.

To all whom it may concern Be it known that I, HARRY BOLENS, a citizenof the United States, residing at Port )Vashington, in the county ofOzaukee and State of Wisconsin, have invented a new and useful AdjustingMeans for the Backs of Type-Writer Chairs, of which the following is aspecification.

My invention relates to improvements in the adjusting means for thebacks of typewriter chairs.

The conventional type-writer chair embodies some well-known style ofwhat is commonly termed iron and which includes the threaded standard orpost arranged adjustably in the base of the chair. the usual yoke, andthe spring-tension device. In this form of iron there is furtherembodied what is commonly termed a rockerarm, the same being merely arigid rearwardly extending extension of the iron and to which the lowerend of the chair-back standard is pivoted in some adjustable manner andmaintained in its adjusted or tilted position to suit the convenienceand ease of the user by means of a hand operated clamping bolt, thelower end of the chair-back standard being bifurcated at its lower endto embrace the usually widened end of the rocker-arm.

Experience proves the fact that this means is not altogether successfulin looking or retaining the chair-back standard in its adjustedpositions, and that when adjusted to suit the convenience of the userand apparently tightened with the usual degree of firmness, it graduallyslips and gets out of adjustment.

My invention has for its principal object to obviate this defect in thisclass of chairconstructions, and, yet at the same time, utilize thiswell-known and generally approved type of chair-adjustment.

My invention, may, therefore, be said to consist in means which whenclamped to secure the chair-back standard to the rockerarm are positiveand capable of preventing the slipping of these parts, all as hereinpointed out, the preferred particular means employed being hereinafterset forth in detail.

Referring to the drawing:

Figure 1 is a side-elevation and partial sectional view (parts beingbroken away) of the conventional type of type-Writer chairadjustmenthereinbefore mentioned and provided with my improvements;

Fig. 2 is a transverse sectional-view of Fig. 1 through the chair-backstandard and rocker-arm, and

Fig. 3 is a vertical longitudinal sectionalview of the same.

Similar numerals of reference indicate similar parts in all the figuresof the drawing. 4

Specifically referring to the conventional type of type-writer chairiron, the same consists of the usual threaded adjusting-post or standard1, which, as will be understood, is adj ustably mounted in a suitabledesign of base (not necessary to be herein shown, and, hence, omitted).Upon the upper end of the adj Listing-post or standard is mounted anywell-known form of adjustment, but embodying the rearwardly extendingrockerarm 2. lhis rocker-arm, it will be understood, projects a shortdistance in rear of the chair-seat (also not herein shown), andterminates in a widened and flattened portion, which for convenience, Iwill term a head 3. The back, aside from its usual appurtenances,includes the standard l, and it has been the habit to bifurcate orrecess the lower end of the same so as to form bifurcations that areparallel and adapted to embrace the head 3 of the rocker-arm. The headof the rocker-arm has its upper edge provided with a transverse notch 5,and a fulcrum-pin 6 rests therein and passes through the bifurcations ofthe back-standard, whereby, as will be obvious, the backstandard iscapable of pivotal movement back and forth. Near its lower end andconcentric with the fulcrum-pin 6, the head 3 of the rocker-arm isprovided with a short curved or segmental slot 7, and coincident withthe same the bifurcations of the backstandards are provided withtransversely alining bolt-holes 8, through which and the aforesaidcurved or segmental slot is passed the adjusting or clamping bolt 9,headed at one end and at its other carrying a nut 10, in the form of asmall hand-wheel.

Thus far, I have described merely the well-known or conventional type oftypewriter chair adjustment, and, as heretofore pointed out, theclamping-means described are inefficient to accomplish the end in view.

To make these means efficient for the purpose intended, first of all, Iprovide the opposite vertical faces of the head 3 of the rocker-arm witha series of vertically disposed serrations or flutes, or grooves, asthey may be better termed, perhaps, all as indicated at 11. Thesegrooves may be more or less in number, different in character or design,as well as disposition, the object being to provide a somewhat roughenedsurface against which the bifurcations of the wooden back-standard maybe clamped by the bolt in contradistinction to the smooth surfaceusually employed, and whereby, when thus clamped, the fiber of'the woodof which the back-standard is composed is, with the same amount ofpressure usually employed, caused to interlock with the grooves orroughened surface aforesaid, so that the slipping tendency of theseparts is to a very great extent, overcome and done away with.

While this may, to a certain extent, accomplish the object sought, yet Iprefer to increase the certainty of doing so in yet an other manner,namely: by gradually tapering the head 3 of the rocker-arm clownwardly.That is to say, by gradually reducing the head 3 in Width from its uppertoward its lower end, whereby to increase the pinching efiect of thebifurcations of the back-standard, which bifurcations, it will beunderstood, are normally parallel. In addition to this, I also graduallytaper the head 3 from its front toward its rear edge, where by, thegreater the weight exerted rearwardly against the chair-back, the morefirmly will the bifurcations be forced into clamping position with thehead- 3 because in such event the tendency of the lower end of theback-standard will be to move for- Ward and this tendency will beopposed b the opposite inclined surfaces of the head 3.

In the manner indicated, it will be obvione that I have converted therather insecure and unsatisfactory clamping-means of the present type ofchair into a most secure and eflicient clamping means. It will beunderstood, of course, that the several means I have suggested allcooperate to produce an adjustment that cannot possibly slip when onceadjusted, and it is my intention at the present to combine such means inthe operative device. At the same time, I also con template using anyone of the means described or combining any two, as I may prefer.

Having described my invention, what I claim, is:

1. The combination in a chair-iron, com

prising a rearwardly disposed rocker-arm terminating in a flattenedhead, the latter furcations, and a wheel-nut' on the end of the boltwhereby the bifurcations may be drawn together to conform to and clampthe opposite inclined surfaces of the head.

2. The combination, in a chair-iron, comprising a rearwardly disposedrocker-arm terminating in a flattened head, the latter having itsopposite surfaces grooved or serrated, notched at its upper end andslotted near its lower end concentrically with the notch, and, further,tapered from its front toward its rear edge and from its upper towardits bottom edge, to form vertical and transverse oppositely inclinedsurfaces, a baclestandard recessed to substantially agree with thewidest or upper edge of the head and to form opposite parallelbifurcations adapted to embrace the same, a fulcrum-pintle passedthrough the bifurcations and resting in the notch of the head, a boltpassed through the bifurcations and through the segmental slot of thehead, and a nut threaded on the bolt at one side of the standard,whereby the bifurcations may be drawn together to conform to and clampthe opposite inclined surfaces of the head.

3. The combination, in a chair-iron, comprising a rearwardly disposedrocker-arm terminating in a flattened widened head having at one side avertically and a horizontally inclined surface, at its upper end a notchand near its lower end a curved slot concentric with the notch, aback-standard pivoted in said notch and extending below its pivot tobear against said surface of th head, a clamping-bolt extending throughthe slot and the baclestandard, and a bindingnut threaded on the boltand adapted to draw the standard snugly and clamp the standard againstsaid inclined surfaces.

In testimony whereof I have signed my name to this specification in thepresence o two subscribing witnesses.

HARRY W. BOLENS Witnesses:

E. ELLIS, W. S. DUVALL.

Copies of this patent may be obtained for five cents each, byaddressing; the Commissioner of Patents. Washington, D. G.

